Pick fob deessing stone



"bnr an einer JOHN C. DEXTER, OF IONIA, MICHIGAN.

PICK FOR DRESSING STONE,

Specification of` Letters Patent No. 3,941, dated March 12,` 1.845.

To all 'whom t may concern:

Be it known that I, JOHN C. DEXTER, of Ionia, in Ionia county and Stateof Michigan, have invented a new and useful Improvement on Mill-Picksfor Dressing French Bur-Millstones; and I do hereby declare that thefollowing is a full, clear, and exact description of the constructionand opera tion of the same, reference being had to the annexed drawings,making a part of this speciiication, in which- Figure l shows a sideview of the instrument when adjusted for use. A, the head, and B, theouter jaw with C, the inner jaw are made of cast iron. A, and B, arecast together in one piece. C, is cast in a separate piece with achannel on the inner side nearly one tenth of an inch in depth and aboutone and a quarter of an inch in width and extending about seven eighthsof the length of the inner jaw C, C, into which channel the point D isinserted in adjusting for use. The point D, is made of the best caststeel, accurately tempered for cutting French bur stone. The thicknessof the point D, is one tenth of an inch; the breadth one and a quarterinch; and the length to correspond with the length of the channel madefor it inthe jaw C. The position of the point in the instrument whenadjusted or use is indicated in Fig. 1, by the dark lines below the endsof the jaws B, and C, and by the dotted lines passing up through the jawC, and through the head A. The point is kept in order for use bygrinding it on a common grindstone; care being taken to grind a bevelequal on both sides of the point so as to preserve the same form as seenin the drawing at Fig. 1. E, the handle, is made of any fine grained,hard wood, and is attached to the instrument by the wrought iron rod F,which runs through it and is screwed into the head by the screw G, andmade firm in the handle by the nut H, screwed on at I. e, e, is a thinferrule of iron or brass designed to strengthen the handle near thehead.

Fig. 2 represents the side of the head and outer jaw B, next the handle;also the hole at G, into which the handle is secured.

Fig. 3, represents the inner jaw C, with the point D, placed in itschannel. rl, in Fig. 3, and Z in Fig. 1, shows the method of extendingthe point D, when worn short by use. CZ is a piece of iron of the sameof the instrument I have found most ccnvenient in stones. j ,j

To adjust this instrument for use I place the point D into the channelmade in C, as seen in Fig. 3 and then slide `it into the socket A Fig.1, and then, holding the instrument by the handle with the sharp end ofthe point D upward, I strike the end b, of the jaw B, B, upon some hardsubstance, as a block of wood, which settles the jaw C, firmly into thesocket A, conlining the point D firmly between the jaws B and C, and theinstrument is then ready for use. )Vlien I wish to release the point forthe my practice of dressing mill purpose of sharpening &c., I turn thesharp end of the point upward and then strike the opposite end of thejaw C, C, on the block of wood which instantly displaces the jaw C, C,and releases the point D.

The invention of this entire instrument I do not claim; but

What I do claim as my invention and desire to secure by Letters Patent,is-

rlhe mode of adjusting and coniining the point D, (Fig. 1,) for use; andreleasing the same, when necessary from the instrument; this iseffected, 1st by constructing that part of the jaw C, C, (Fig. 1)extending from c1, to c2, (Fig. 1,) in a tapering form; so that the jawC, C, shall be at c1 about two thirds as thick as at 02,' 2d, by makingthe hole through the socket A (Fig. 1,) of the same degree of taper asthe jaw C, C, and of the proper size to exactly embrace the jaw C, C,when driven home to its place, as seen in (Fig. 1) 3d, by making achannel on the side of the jaw C, G, (Fig. 1,) next to the jaw B, B,about one tenth of an inch deep, about seven eighths the length of thejaw C, C, terminating the channel about one inch from the end c1; 4th,by making the point D7 D, (Fig. l), about o-ne thirty-second part of aninch thicker than the depth of the channel in C, C.

To adjust the point and secure it firmly in the instrument for use, Iplace the point D into the Channel made in C, C, as seen in Fig. 3, thenholding the point in the channel, I slide the point D, and the jaw C, C,into the socket A (Fig. I); then, holding the instrument by the handlewith the sharp end of the point upward, I strike the end ZJ of the jawB, B7 upon some hard substance, as a small block of wood; which by theforce of the blow, Causes the jaw C, C, to settle rmly into its socket,and produce a pressure against the point D, which secures itrmly in itsplaee.- The instrument is then ready'for use. lVhen I wish to releasethe point for sharpening, Sac., I hold the instrument by the handle withthe sharp end of the point upward, and strike the end 01, of the jaw C,C, upon the block of wood, which instantly displaces the jaw C, C, andreleases the point.

JOHN C. DEXTER. lVitnesses:

MASON HENSEY, A. F. CARR.

